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Testing the consistency of theoretical income distributions with the empirical ones is a very
important problem in income distribution analysis. Most of well known goodness-of-fit tests
cannot be used to solve this problem because the parameters of the population are usually
not known and the samples are very large.
In the paper we present the main properties of the Cox statistic which is based...
Dynamic schemes of hedging against currency risk are carefully structured procedures, which
should be carried out immediately during continuous transaction monitoring in case of changes in
currency value. Hence, it can be described as selective, continuous preventing of open positions in
currency options. The hedging techniques which reduce the loss without excluding the profits from
currency...
The selection of proper SPC charts is essential to effective statistical process control
implementation and use. It is important to use best chart for the given situation and need.
Using Shewhart quality control charts to detecting small process shill is not effective. This
paper shows that the cumulative-sum control charts (CUSUM) and Exponentially Weighted
Moving Average control charts (EWMA)...
An example of the application of point processes observed with noise are aerial photographs
of forests with the aim of estimating the actual number of trees on a given area. Lund and
Rudemo (2000) proposed a model useful in this context, basing on the number of “trees
candidates” visible on the photograph. The parameters of conditional likelihood function were
estimated taking into account such...
This paper will present alternative methods of valuation of coefficients beta. The estimation
of future coefficients beta can be received by delimitation the coefficients beta from past data
and use these coefficients as the estimation of future coefficients beta. At the beginning we
will present Blume method and in the second section Vasicek method.
Classic theory of statistical inference gives us methods and verification of hypothesis for
simple samples (observations are stochastically independent and have the same distribution).
Because of costs and effectiveness of research we use simple samples. Observations in these
samples are stochastically dependent and have different distribution.
The paper presents problems in estimation and verifications...
The relations between characteristics for subpopulations and for the whole population are
very important in small area investigations.
In the paper there are proposed testing procedures for verification of hypothesis which
says that there is no difference between the ratio of small area mean and population mean
for analysed variable and auxiliary variable. The properties of one considered procedure...
Retail banking deals with servicing consumer credits and it constitutes one of the major
banking activities. A customer applying for the credit fills in the application which is basis
to evaluated of his creditworthiness.
The paper considers the problem of evaluation to which of the two groups the person
applying for a credit should be assigned to: a) those who possess the creditworthiness; b)...
Decision tree is a graphical presentation of the recursive partitioning the learning set into
homogenous subsets considering dependent variable y.
If dependent variable у is nominal we deal with nonparametric discriminant analysis
(classification trees), when у is numerical - with nonparametric regression analysis (regression
trees).
The aim of the paper is to present some applications of regression...
W artykule porównywano własności teoretycznych i empirycznych rozkładów płac i dochodów
z punktu widzenia możliwości ich zastosowania do analizy rozkładów płac w Polsce.
W szczególności rozważano takie rozkłady, jak logarytmiczno-normalny czy Daguma. Rozkłady
teoretyczne, wykazujące wysoką zgodność z empirycznymi, zostały następnie wykorzystane do
estymacji miar nierównomierności. Estymację przeprowadzono...
The paper presents path-dependent options with a single barrier in terms of
path-independent standard options. The key to providing this result is put-call symmetry,
which is assumed to hold when the underlying first reaches the barrier price.
One of well-known groups of cluster analysis methods is the group of methods
based on density estimation. In the paper we propose a new method of defining dusters
which consists of two steps. In the first step we find local maxima of the joint distribution
thus establishing clusters centres. In the second step we assign observations to one of existing
clusters centres. The number of clusters is...
Classification and regression trees are very popular and attractive types of
classifiers, widely used to solve decision-making problems in different fields of science.
The study was conducted to identify preoperative risk factors associated with morbidity
outcome among patients undergoing isolated Coronary Artery Bypass Grafting (CABG) and
to develop some classification rules assigning patients...
It became more important to recognize customer expectations and to oiler
product properties, which convince customer to buy the analyzed product.
In customer loyalty and satisfaction analysis methods, classification trees play a very
important role.
The aim of the paper is to present an application of tree - structured models to analyze
product properties influencing buying decision of the target...
The interest in the problem of credit risk has significantly increased within the
last few dozen years. Scientific literature presents a lot of methods of the credit risk limitation
whereas banks try, with various results, to bring proposed methods into effect. Credit derivatives
have been ones of the most important innovations of the last years in the world
financial system. Their innovation...
The basic characteristic describing the behaviour of the random variable is its density
function. Kernel density estimation is one of the most widely used nonparametric density
estimations. In the process of constructing the estimator we have to choose two parameters of
the method: the kernel function K(u) and smoothing parameter h (bandwidth). In the paper,
kernel method is discussed in detail,...
Nonparametric sequential methods allow to estimate unknown parameter of random variable
distribution, when the distribution of the variable is unknown. We can apply these methods
to different sampling designs.
This paper contains a proposal of applying simulation methods to estimate the variance
of a nonparametric estimator of mean. An application of bootstrap methods to estimate the
variance...
Bayesian networks are directed acyclic graphs that represent dependencies between
variables in a probabilistic model. They are becoming an increasingly important area fог
research and applications in the entire field of Artificial Intelligence. This paper explores the
nature of implications for Bayesian networks beginning with an overview and comparison of
inferential statistics and Bayes’ Theorem...
The foundation of insurance company activity is proper adjustment of premium level to
the risk level of the insured. The insurer usually groups policies in portfolios characterized
with similar risk.
However, there exist risk factors not observable directly, having impact on the claim size
and frequency. An important issue, therefore is the assessment of portfolio homogeneity.
The purpose of...
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